1. Field of the Invention
The invention relates to an auxiliary heater arrangement for a motor vehicle, with an auxiliary heater, a catalytic converter for catalytic post-combustion of the exhaust gas, a muffler for damping of the noise caused by the exhaust gas, and an exhaust line for removing exhaust gas from the auxiliary heater. Furthermore, the invention relates to an auxiliary heater muffler which is suitable for installation on the exhaust line of an auxiliary heater arrangement, and an auxiliary heater catalytic converter and a motor vehicle with the initially mentioned auxiliary heater arrangement.
2. Field of the Invention
An auxiliary heater arrangement of the aforementioned type is known from U.S. Pat. No. 4,923,033. The motor vehicle auxiliary heater device described there has a combustion chamber in which there is a muffler and which itself is made as a muffler. The muffler damps the combustion noise and the combustion gas noise by absorption and by reflection. Furthermore, the muffler can also be designed such that it cleans the combustion gases, for example, by catalytic post-combustion and filtering out the soot particles, when the heater is operated with diesel as the liquid fuel. Depending on the heater type, its own muffler must be made and warehoused for installation.
European Patent EP 0 638 776 B1 discloses a liquid fueled heater for a motor vehicle which operates independently of the engine and which has a combustion chamber, a downstream fire tube and a heat exchanger located concentrically about the combustion chamber and to the fire tube, in which the exhaust gas, after emerging from the fire tube, is deflected and routed through the heat exchanger to the exhaust outlet connector. Between the outside wall of the combustion chamber or the fire tube and the inside wall of the heat exchanger, there is a catalytically active unit. A unit installed in this manner must be matched to the contour of the ribs of the heat exchanger, and therefore, warehoused individually for each heater type. In addition, the installation of the knit is relatively complex and can only be performed manually.
U.S. Pat. No. 5,206,467 discloses a muffler for an internal combustion engine. Within the muffler, a catalytically active layer is located underneath an acoustic damping layer. In an internal combustion engine, the noise of the exhaust ejected from the individual cylinders in rapid sequence, which noise is to be damped, is completely different from the noise which is produced by the almost continuously burning flame of an auxiliary heater. Moreover, the temperature and the composition of the exhaust are different. A muffler for an internal combustion engine is therefore unsuited for an auxiliary heater.